Abstract

An application structure is best modeled first as a conceptual schema, and then mapped to an internal schema for the target DBMS. Different but equivalent conceptual schemas often map to different internal schemas, so performance may be improved by applying conceptual transformations prior to the standard mapping. This paper discusses recent advances in the theory of schema transformation and optimization within the framework of ORM (Object-Role Modeling). New aspects include object relativity, complex types, a high level transformation language and update distributivity.

on leave from Dept of Computer Science, University of Queensland

partly supported by an Australian Research Council grant, titled “An expert system for improving database design”